A satellite or digital cable distribution system may provide television programs to subscribers of the distribution system. Typically, satellite and digital cable distribution systems include a set-top box that receives and decrypts the television signal such that a television program may be viewed by the user. In many satellite distribution systems, the television signal may be broadcast by a satellite, received by a satellite dish antenna and decoded by the set-top box. In digital cable systems, the television signal is typically transmitted to the user through a cable connected directly to the set-top box.
Generally, set-top boxes connected to a distribution system may receive commands from a satellite via the distribution system, to configure and/or update the operating software or access privileges stored in the set-top box. For example, upon purchase by a user, a headend of the distribution system may transmit a command to a user's set-top box to provide the user's system with access to purchased content, such as a pay-per-view movie or channel. This command typically includes instructions to the set-top box's software to unlock the content or other instructions and is often addressed or encrypted to a unique smart card associated with the set-top box. Further, in most systems, only the specific smart card to which the command is addressed may decrypt the command. Thus, by request of a user, a command may be broadcast across the distribution system to several set-top boxes of the system simultaneously such that only the set-top box with a matching smart card number to the encrypted command may decrypt and execute the command.